The U.S. Patent to Szemeredi disclosed a useful plastic valve structure intended to facilitate the removal and replacement by a householder without any tools whatsoever. One of the problems in the Szemeredi device is that it requires the use of a key movable transversely of the valve recess cooperable with an undercut slot at one side of the brass body, and two rectangular holes at the opposite side of the brass body. Such slots and holes require somewhat costly machining operations that are desirably avoided. Furthermore, the Szemeredi valve structure requires the use of a bulbous seal member clamped or compressed against a ported inlet partition of the brass body. Proper seating of the static seal about the inlet required accurate location of the locking slots of the body with reference to the inlet partition.
Another annoyance with the Szemeredi structure is the forgetfulness of the householder. It is not uncommon for the householder to attempt removal of a plumbing valve without shutting off the water supply to the fixture. Once the Szemeredi valve is removed, large volumes of water may be released.
The primary object of this invention is to provide an improved valve structure, designed for installation, removal and replacement without tools, a valve structure that signals the presence of water pressure before removal, and a valve structure that requires only the simplest of machining operations on the brass body.